Deficiencies in dietary antioxidants have been implicated in a variety of ocular disorders. Our initial experiments indicate that rats deficient in physiological antioxidants accumulate a fluorescent pigment in the RPE which is characteristic of in vivo lipid auto-oxidation. The proposed research plan has five major objectives. (1) To continue to study the physiological mechanisms that protect ocular tissues from oxidative damage and to specifically determine the synergistic role of various dietary antioxidants in either promoting or inhibiting the build-up of the RPE fluorescent pigment. (2) To correlate any functional damage in the retina-RPE with antioxidant status and photodynamic stress. (3) To define the relationship between fluorescent pigment accumulation and alterations in lipid metabolism, subcellular organelles, and the functioning of the RPE phagolysosomal system. (4) Study the effects of prostaglandins and cyclic nucleotides on the functioning of the RPE phagolysosomal system in cells in tissue culture. (5) Initiate a search for surface recognition sites between ROS and RPE cells in culture.